CS253 HW3: Options                

Description                

Write a C++ program called opts.cc that behaves as mf.cc from HW2, except that it accepts a properties file and command-line options. These options determine which properties to emit. Unlike HW2, the property counts are labeled with the two-letter abbreviation for the property (e.g., Lu) and not the words (e.g., Letter, uppercase). This means that you have to pay attention to both characters of the property.                 

Properties File                

The properties file is no longer necessarily ~cs253/pub/ASCII-properties. The name of a similar file is a new, required, first (after options) argument. It may have fewer lines than ASCII-properties did. It may not describe all possible characters, and may not be in order.                 

For example, here is a properties file that only describes hexadecimal chars (0–9, A–F) space, and newline. Its property names are different than those in ASCII-properties. It is available in ~cs253/pub/hex-props.                 

    41 Le
    42 Le
    43 Le
    44 Le
    45 Le
    46 Le
    30 Di
    31 Di
    32 Di
    33 Di
    34 Di
    35 Di
    36 Di
    37 Di
    38 Di
    39 Di
    20 Sp
    0A Nl

Note the completely different properties in that file:

• Le: Letter
• Di: Digit
• Sp: Space
• Nl: Newline

Options                

The options are the properties from the second field in the properties file. For example, if Cc, Lu, and Nd are all properties, then -Cc, -Lu, and -Nd are valid options. The actual list of valid properties must be read from the properties file at runtime.                 

There is one special option: -all. It indicates that all property counts from the properties file should be displayed.                 

Sample Runs                

Here are several sample runs. “%” is my prompt:                 

    % g++ -Wall opts.cc 
    % cat a
    This is "test data" for HW2.
    Don't <ignore> it!
    % cat b
    Wed Jan  4 14:53:50 MST 2017
    % cat h
    A1B2C3
    % ./a.out -Lu ~cs253/pub/ASCII-properties a b
    Lu: 9
    % ./a.out -Sm -Ll ~cs253/pub/ASCII-properties a b
    Ll: 31
    Sm: 2
    % ./a.out -Zs -Lu -Sk ~cs253/pub/ASCII-properties b
    Lu: 5
    Sk: 0
    Zs: 6
    % ./a.out -all ~cs253/pub/hex-props h
    Di: 3
    Le: 3
    Nl: 1
    Sp: 0
    % ./a.out -all ~cs253/pub/ASCII-properties a b
    Cc: 3
    Ll: 31
    Lu: 9
    Nd: 12
    Pc: 0
    Pd: 0
    Pe: 0
    Po: 7
    Ps: 0
    Sc: 0
    Sk: 0
    Sm: 2
    Zs: 13
    % ./a.out -all ~cs253/pub/ASCII-properties ~cs253/pub/hamlet.txt 
    Cc: 10412
    Ll: 119683
    Lu: 16350
    Nd: 0
    Pc: 0
    Pd: 422
    Pe: 261
    Po: 7418
    Ps: 261
    Sc: 0
    Sk: 0
    Sm: 48
    Zs: 27713
    % ./a.out ~cs253/pub/ASCII-properties b -Zs
    ./a.out: can’t read -Zs

Requirements                

The requirements are the same as those for HW2, plus:                 

• All error messages go to standard error, and include the program name. After emitting the message, the program must stop, without displaying the summary.
• Options come first, before filenames, in the command line. Therefore, ./a.out propfile b -Zs should result in treating -Zs as a filename, which should generate an error message complaining that it doesn’t exist (most likely).
• If the property file can’t be read, emit an error message, including the property file name.
• If the property file isn’t given, emit an error message.
• If an invalid option is encountered (not -all or one of the properties from the property file), emit an error message, including the offending argument.
• The characters described in the properties file will be in the range 0–0x7F, though there may be fewer lines, and the lines may be in any order.
• You may assume that properties file is correctly formatted:
  • Two hex digits
  • followed by a space
  • followed by A–Z and then a–z
  • and then a newline.
• If a character is encountered that is not described in the given properties file, including being <0 or ≥128, emit an error message, including the filename (of the file that contained the bad character), and the hexadecimal representation of the offending character.
• The output may be produced in any order. That is, if both -Sm and -Ll are specified, the Sm count could be the first line, or the second. We will sort the output of your program before examining it.
• We may run your program with one of the properties files shown above, or with other files with different names and different contents.

Ask                

If you have any questions about the requirements, ask. In the real world, your programming tasks will almost always be vague and incompletely specified. Same here.                 

How to submit your homework:                

Use web checkin, or Linux checkin:                 

    ~cs253/bin/checkin HW3 opts.cc

How to receive negative points:                

Turn in someone else’s work.